Did you clear your cookies correctly? Try again. I get consistent behavior if and only if I clear my cookies all the time. (Hint: There is a sleep timer variable.)


....

To recap my independent investigation:

Repeatable behavior if you clear your cookies correctly:
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=474505#Post474505

I managed to single out and block the two(2) malicious javascripts, thus ending the unwanted behavior on my personal browser only:
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=474507#Post474507

Root cause found in (hacked?) ubb scripting, which launches the two(2) malicious javascripts:
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=474547#Post474547

...


Finally, here's the culprit. Can an admin delete this one evil line of code? (See attachment for full scale.)

image.js on the zorro server:
http://www.opserver.de/ubb7/ubb_js/image.js

image.js on the UBB.threads server (the source):
https://www.ubbcentral.com/forums/ubb_js/image.js